1. Field of the Invention
Embodiments of the present invention generally relate to equipment for performing semiconductor device fabrication, and more particularly, to a process kit for partially covering a surface of a substrate support.
2. Description of the Related Art
Substrate supports are used for supporting a semiconductor substrate (or semiconductor wafer or wafer as referred to herein) within semiconductor processing equipment such as a plasma processing chamber. A substrate support generally holds a substrate in a stationary position during processing of the substrate, e.g., during material deposition or etching, by use of an electrostatic chuck or the like.
During plasma processes, such as plasma assisted chemical vapor deposition (CVD) processes, components of the substrate support may become covered with deposited materials from the process. Such materials may include oxide or fluoride powders, and may damage the substrate support or may flake off or be removed from the substrate support and contaminate the substrate being processed. Moreover, exposed metal surfaces of the substrate support may lead to arcing in the plasma process and metal contamination of the substrate and/or the chamber. To mitigate these problems, a process kit may be disposed atop and/or around the substrate support to prevent such damage and/or contamination. However, contaminants deposited on the process kit proximate the wafer edge may still contaminate the wafer being processed. Moreover, in certain processes, materials sputtered off of the substrate proximate the substrate edge may be deposited upon the process kit near the substrate edge, thereby increasing the buildup of materials on the process kit and shortening the mean time between cleaning.
Accordingly, there is a need for an improved process kit.